Sorry, it is very counter intuitive to me.
So what you say is this: if there is an open terminal before chmod 700, then I
can use that terminal to access "apple", but after I close terminal B, there is
no way to access that apple directory? Neither with a shall window, nor with
another software?
In some cases this may lead to serious security issues, doesn't it?
Let me ask this specific question: is there any way to access apple, other than
the already open terminal B? If not, then it is ok, but there is any way to
access apple, then I have to do recursive chown and chmod to make sure nobody
can access anything below /opt/experiment.